[PATCH v1 3/3] drm/panel: Add support for otm8009a panel driver
Philippe CORNU
philippe.cornu at st.com
Thu Jul 6 14:44:48 UTC 2017
On 07/05/2017 11:28 AM, Andrzej Hajda wrote:
> On 04.07.2017 18:30, Philippe CORNU wrote:
>> This patch adds Orise Tech otm8009a 3.97" 480x800 TFT LCD
>> panel driver (MIPI-DSI video mode). The panel backlight is
>> managed through the DSI link. This panel driver is used in
>> several STM32 boards.
>>
>> Signed-off-by: Philippe CORNU <philippe.cornu at st.com>
>> ---
>> drivers/gpu/drm/panel/Kconfig | 9 +
>> drivers/gpu/drm/panel/Makefile | 1 +
>> drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 517 +++++++++++++++++++++++
>> 3 files changed, 527 insertions(+)
>> create mode 100755 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>>
>> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
>> index d84a031..c1c9291 100644
>> --- a/drivers/gpu/drm/panel/Kconfig
>> +++ b/drivers/gpu/drm/panel/Kconfig
>> @@ -117,4 +117,13 @@ config DRM_PANEL_SITRONIX_ST7789V
>> Say Y here if you want to enable support for the Sitronix
>> ST7789V controller for 240x320 LCD panels
>>
>> +config DRM_PANEL_ORISETECH_OTM8009A
>> + tristate "Orise Tech otm8009a 480p dsi 2dl video mode panel"
>> + depends on OF
>> + depends on DRM_MIPI_DSI
>> + depends on BACKLIGHT_CLASS_DEVICE
>> + help
>> + Say Y here if you want to enable support for Orise Tech OTM8009A
>> + 480x800 DSI panel
>> +
>> endmenu
>> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
>> index 9f6610d..ac798f3 100644
>> --- a/drivers/gpu/drm/panel/Makefile
>> +++ b/drivers/gpu/drm/panel/Makefile
>> @@ -10,3 +10,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
>> obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
>> obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
>> obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
>> +obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
>> \ No newline at end of file
>> diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>> new file mode 100755
>> index 0000000..7aefc09
>> --- /dev/null
>> +++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>> @@ -0,0 +1,517 @@
>> +/*
>> + * Copyright (C) STMicroelectronics SA 2017
>> + *
>> + * Authors: Philippe Cornu <philippe.cornu at st.com>
>> + * Yannick Fertre <yannick.fertre at st.com>
>> + *
>> + * License terms: GNU General Public License (GPL), version 2
>> + */
>> +#include <drm/drmP.h>
>> +#include <drm/drm_mipi_dsi.h>
>> +#include <drm/drm_panel.h>
>> +#include <linux/backlight.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <video/mipi_display.h>
>> +
>> +#define DRV_NAME "orisetech_otm8009a"
>> +
>> +#define OTM8009A_BACKLIGHT_DEFAULT 240
>> +#define OTM8009A_BACKLIGHT_MAX 255
>> +
>> +struct otm8009a {
>> + struct device *dev;
>> + struct drm_panel panel;
>> + struct backlight_device *bl_dev;
>> + struct gpio_desc *reset_gpio;
>> + bool prepared;
>> + bool enabled;
>> +};
>> +
>> +static const struct drm_display_mode default_mode = {
>> + .clock = 32729,
>> + .hdisplay = 480,
>> + .hsync_start = 480 + 120,
>> + .hsync_end = 480 + 120 + 63,
>> + .htotal = 480 + 120 + 63 + 120,
>> + .vdisplay = 800,
>> + .vsync_start = 800 + 12,
>> + .vsync_end = 800 + 12 + 12,
>> + .vtotal = 800 + 12 + 12 + 12,
>> + .vrefresh = 50,
>> + .flags = 0,
>> + .width_mm = 52,
>> + .height_mm = 86,
>> +};
>> +
>> +static inline struct otm8009a *panel_to_otm8009a(struct drm_panel *panel)
>> +{
>> + return container_of(panel, struct otm8009a, panel);
>> +}
>> +
>> +static void otm8009a_dcs_write_buf(struct otm8009a *ctx, const void *data,
>> + size_t len)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +
>> + if (mipi_dsi_dcs_write_buffer(dsi, data, len) < 0)
>> + DRM_WARN("mipi dsi dcs write buffer failed");
>
> New line at the end of string.
>
> I see another way of fighting with error handling, its drawback is that
> failure does not prevent further execution.
> Since I am lost what error handling pattern is currently accepted in
> panels subsystem, I cannot advice if this should be changed.
>
Hi Andrzef,
First of all, a big *THANK YOU* for this nice code review. Your comments
are very relevant :-)
Regarding the error management, there are actually several solutions to
deal with errors but I confess that for the moment none really convinced
me... that is why I proposed here the *minimal solution of the trace*...
>> +}
>> +
>> +#define dcs_write_seq(seq...) \
>> + do { \
>> + static const u8 d[] = { seq }; \
>> + otm8009a_dcs_write_buf(ctx, d, ARRAY_SIZE(d)); \
>> + } while (0)
>
> It is up to your preferences, but I think "do {} while(0)" construct is
> kind of workaround and is obsoleted in favor of ({ ... }) statement
> expressions[1].
> More serious issue is that you are using ctx implicitly, it should be
> added as macro argument.
>
> [1]: https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
>
I will follow your proposal, thank you so much for these information.
>> +
>> +static int otm8009a_init_sequence(struct otm8009a *ctx)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> + int ret;
>> +
>> + /*
>> + * CMD2_ENA1: Enter in Command 2 mode, enable write function of
>> + * Command 2 & enable parameter shift function.
>> + * The 3 following sequences allow to enable ORISE command mode.
>> + */
>> + dcs_write_seq(0xFF, 0x80, 0x09, 0x01);
>
> I think it would be more readable if you use defines for DCS and MCS
> (Manufacturer Command Set), for example:
> #define MCS_CMD2 0xff
> ...
> dcs_write_seq(ctx, MCS_CMD2, 0x80, 0x09, 0x01);
>
>> + dcs_write_seq(0x00, 0x80);
>> + dcs_write_seq(0xFF, 0x80, 0x09);
>
> Since the patterns with address shifting is repeated multiple times
> maybe better would be to define helper for it, for example:
> #define MCS_ADRSFT 0x00
> #define dcs_write_cmd_at(ctx, cmd, addr, seq...) ({\
> dcs_write_seq(ctx, MCS_ADRSFT, addr);\
> dcs_write_seq(ctx, cmd, seq);\
> })
>
> And use it this way:
> dcs_write_cmd_at(MCS_CMD2, 0x80, 0x80, 0x09);
>
Very good & clever proposals, I will implement them in v2. Many thanks
>> +
>> + /*
>> + * Starting from here, address shift needs to be set before sending
>> + * a new command. You can find an example in the next sequence...
>> + * SD_PCH_CTRL (0xC480) Source Driver Precharge Control (SD_PT=GND)
>> + */
>> + dcs_write_seq(0x00, 0x80); /* address shift set to 0x80 */
>> + dcs_write_seq(0xC4, 0x30); /* 0xC480 parameter 1 is 0x30 */
>> + mdelay(10);
>> +
>> + /* Not documented (0xC48A) */
>> + dcs_write_seq(0x00, 0x8A);
>> + dcs_write_seq(0xC4, 0x40);
>> + mdelay(10);
>> +
>> + /* PWR_CTRL4 (0xC5B0) Power Control Setting 4 for DC Voltage */
>> + dcs_write_seq(0x00, 0xB1); /* 178th parameter */
>> + dcs_write_seq(0xC5, 0xA9);
>> +
>> + /* PWR_CTRL2 (0xC590) Power Control Setting 2 for Normal Mode */
>> + dcs_write_seq(0x00, 0x91); /* 146th parameter */
>> + dcs_write_seq(0xC5, 0x34);
>> +
>> + /* P_DRV_M (0xC0B4) Panel Driving Mode */
>> + dcs_write_seq(0x00, 0xB4);
>> + dcs_write_seq(0xC0, 0x50);
>> +
>> + /* VCOMDC (0xD900) VCOM Voltage Setting */
>> + dcs_write_seq(0x00, 0x00);
>> + dcs_write_seq(0xD9, 0x4E);
>> +
>> + /* OSC_ADJ (0xC181) Oscillator Adjustment for Idle/Normal mode */
>> + dcs_write_seq(0x00, 0x81);
>> + dcs_write_seq(0xC1, 0x66); /* 65Hz */
>> +
>> + /* RGB_VIDEO_SET (0xC1A1) RGB Video Mode Setting */
>> + dcs_write_seq(0x00, 0xA1);
>> + dcs_write_seq(0xC1, 0x08);
>> +
>> + /* PWR_CTRL2 (0xC590) Power Control Setting 2 for Normal Mode */
>> + dcs_write_seq(0x00, 0x92); /* 147th parameter */
>> + dcs_write_seq(0xC5, 0x01);
>> + dcs_write_seq(0x00, 0x95); /* 150th parameter */
>> + dcs_write_seq(0xC5, 0x34);
>> + dcs_write_seq(0x00, 0x94); /* 149th parameter */
>> + dcs_write_seq(0xC5, 0x33);
>> +
>> + /* GVDD/NGVDD (0xD800) */
>> + dcs_write_seq(0x00, 0x00);
>> + dcs_write_seq(0xD8, 0x79, 0x79);
>> +
>> + /* SD_CTRL (0xC0A2) Source Driver Timing Setting */
>> + dcs_write_seq(0x00, 0xA3); /* 164th parameter */
>> + dcs_write_seq(0xC0, 0x1B);
>> +
>> + /* PWR_CTRL1 (0xC580) Power Control Setting 1 */
>> + dcs_write_seq(0x00, 0x82); /* 131st parameter */
>> + dcs_write_seq(0xC5, 0x83);
>> +
>> + /* SD_PCH_CTRL (0xC480) Source Driver Precharge Control */
>> + dcs_write_seq(0x00, 0x81); /* 130th parameter */
>> + dcs_write_seq(0xC4, 0x83);
>> +
>> + /* RGB_VIDEO_SET (0xC1A1) RGB Video Mode Setting */
>> + dcs_write_seq(0x00, 0xA1);
>> + dcs_write_seq(0xC1, 0x0E); /* todo previously we wrote 0x08... */
>> +
>> + /* PANSET (0xB3A6) Panel Type Setting */
>> + dcs_write_seq(0x00, 0xA6);
>> + dcs_write_seq(0xB3, 0x00, 0x01);
>> +
>> + /* GOAVST (0xCE80) GOA VST Setting */
>> + dcs_write_seq(0x00, 0x80);
>> + dcs_write_seq(0xCE, 0x85, 0x01, 0x00, 0x84, 0x01, 0x00);
>> +
>> + /* GOACLKA1 (0xCEA0) GOA CLKA1 Setting */
>> + dcs_write_seq(0x00, 0xA0);
>> + dcs_write_seq(0xCE, 0x18, 0x04, 0x03, 0x39, 0x00, 0x00, 0x00, 0x18,
>> + 0x03, 0x03, 0x3A, 0x00, 0x00, 0x00);
>> +
>> + /* GOACLKA3 (0xCEB0) GOA CLKA3 Setting */
>> + dcs_write_seq(0x00, 0xB0);
>> + dcs_write_seq(0xCE, 0x18, 0x02, 0x03, 0x3B, 0x00, 0x00, 0x00, 0x18,
>> + 0x01, 0x03, 0x3C, 0x00, 0x00, 0x00);
>> +
>> + /* GOAECLK (0xCFC0) GOA ECLK Setting */
>> + dcs_write_seq(0x00, 0xC0);
>> + dcs_write_seq(0xCF, 0x01, 0x01, 0x20, 0x20, 0x00, 0x00, 0x01, 0x02,
>> + 0x00, 0x00);
>> +
>> + /* Not documented */
>> + dcs_write_seq(0x00, 0xD0);
>> + dcs_write_seq(0xCF, 0x00);
>> +
>> + /* PANCTRLSET1-8 (0xCB80-0xCBF0) Panel Control Setting 1-8 */
>> + dcs_write_seq(0x00, 0x80);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00);
>> + dcs_write_seq(0x00, 0x90);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xA0);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xB0);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xC0);
>> + dcs_write_seq(0xCB, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xD0);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x04,
>> + 0x04, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xE0);
>> + dcs_write_seq(0xCB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xF0);
>> + dcs_write_seq(0xCB, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
>> + 0xFF, 0xFF);
>> +
>> + /* PANU2D1-3 (0xCC80-0xCCA0) Panel U2D Setting 1-3 */
>> + dcs_write_seq(0x00, 0x80);
>> + dcs_write_seq(0xCC, 0x00, 0x26, 0x09, 0x0B, 0x01, 0x25, 0x00, 0x00,
>> + 0x00, 0x00);
>> + dcs_write_seq(0x00, 0x90);
>> + dcs_write_seq(0xCC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x26, 0x0A, 0x0C, 0x02);
>> + dcs_write_seq(0x00, 0xA0);
>> + dcs_write_seq(0xCC, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> +
>> + /* PAND2U1-3 (0xCCB0-0xCCD0) Panel D2U Setting 1-3 */
>> + dcs_write_seq(0x00, 0xB0);
>> + dcs_write_seq(0xCC, 0x00, 0x25, 0x0C, 0x0A, 0x02, 0x26, 0x00, 0x00,
>> + 0x00, 0x00);
>> + dcs_write_seq(0x00, 0xC0);
>> + dcs_write_seq(0xCC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x25, 0x0B, 0x09, 0x01);
>> + dcs_write_seq(0x00, 0xD0);
>> + dcs_write_seq(0xCC, 0x26, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> +
>> + /* PWR_CTRL1 (0xC580) Power Control Setting 1 */
>> + dcs_write_seq(0x00, 0x81); /* 130th parameter */
>> + dcs_write_seq(0xC5, 0x66);
>> +
>> + /* Not documented */
>> + dcs_write_seq(0x00, 0xB6);
>> + dcs_write_seq(0xF5, 0x06);
>> +
>> + /* GMCT2.2P (0xE100) Gamma Correction 2.2+ Setting */
>> + dcs_write_seq(0x00, 0x00);
>> + dcs_write_seq(0xE1, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10, 0x0B, 0x0A,
>> + 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A, 0x01);
>> +
>> + /* GMCT2.2N (0xE100) Gamma Correction 2.2- Setting */
>> + dcs_write_seq(0x00, 0x00);
>> + dcs_write_seq(0xE2, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10, 0x0B, 0x0A,
>> + 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A, 0x01);
>> +
>> + /* Exit CMD2 mode */
>> + dcs_write_seq(0x00, 0x00);
>> + dcs_write_seq(0xFF, 0xFF, 0xFF, 0xFF);
>> +
>> + /* OTM8009a NOP */
>> + dcs_write_seq(0x00, 0x00);
>
> It looks more like resetting shift address, not NOP command.
>
Yes, you are right, bad copy/paste, I will update it.
>> +
>> + ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
>> + if (ret)
>> + return ret;
>> +
>> + /* Wait for sleep out exit */
>> + mdelay(120);
>> +
>> + /* Default portrait 480x800 rgb24 */
>> + dcs_write_seq(MIPI_DCS_SET_ADDRESS_MODE, 0x00);
>> + dcs_write_seq(MIPI_DCS_SET_COLUMN_ADDRESS, 0x00, 0x00, 0x01, 0xDF);
>> + dcs_write_seq(MIPI_DCS_SET_PAGE_ADDRESS, 0x00, 0x00, 0x03, 0x1F);
>> + dcs_write_seq(MIPI_DCS_SET_PIXEL_FORMAT, 0x77);
>
> I think some of above DCS commands have corresponding helper functions.
>
Yes, you are right, lazy I am :), I will update it. Many thanks.
>> +
>> + /* Disable CABC feature */
>> + dcs_write_seq(0x55, 0x00);
>> +
>> + ret = mipi_dsi_dcs_set_display_on(dsi);
>> + if (ret)
>> + return ret;
>> +
>> + /* OTM8009a NOP */
>> + dcs_write_seq(0x00, 0x00);
>> +
>> + /* Send Command GRAM memory write (no parameters) */
>> + dcs_write_seq(MIPI_DCS_WRITE_MEMORY_START);
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_disable(struct drm_panel *panel)
>> +{
>> + struct otm8009a *ctx = panel_to_otm8009a(panel);
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> + int ret;
>> +
>> + if (!ctx->enabled)
>> + return 0; /* This is not an issue so we return 0 here */
>> +
>> + /* Power off the backlight. Note: end-user still controls brightness */
>> + ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
>> + ret = backlight_update_status(ctx->bl_dev);
>> + if (ret)
>> + return ret;
>> +
>> + ret = mipi_dsi_dcs_set_display_off(dsi);
>> + if (ret < 0)
>> + return ret;
>> +
>> + ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
>> + if (ret < 0)
>> + return ret;
>> +
>> + msleep(120);
>> +
>> + ctx->enabled = false;
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_unprepare(struct drm_panel *panel)
>> +{
>> + struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +
>> + if (!ctx->prepared)
>> + return 0;
>> +
>> + if (ctx->reset_gpio) {
>> + gpiod_set_value_cansleep(ctx->reset_gpio, 0);
>> + msleep(20);
>> + }
>> +
>> + ctx->prepared = false;
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_prepare(struct drm_panel *panel)
>> +{
>> + struct otm8009a *ctx = panel_to_otm8009a(panel);
>> + int ret;
>> +
>> + if (ctx->prepared)
>> + return 0;
>> +
>> + if (ctx->reset_gpio) {
>> + gpiod_set_value_cansleep(ctx->reset_gpio, 0);
>> + msleep(20);
>> + gpiod_set_value_cansleep(ctx->reset_gpio, 1);
>> + msleep(20);
>
> Specs says reset gpio is active low, so I guess it should be fixed in
> bindings, dts and in driver.
>
> Regards
> Andrzej
>
100% correct! I am fixing it, many thanks for your review.
Best regards,
Philippe
>> + }
>> +
>> + ret = otm8009a_init_sequence(ctx);
>> + if (ret)
>> + return ret;
>> +
>> + ctx->prepared = true;
>> +
>> + /* Power on the backlight. Note: end-user still controls brightness */
>> + ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
>> + backlight_update_status(ctx->bl_dev);
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_enable(struct drm_panel *panel)
>> +{
>> + struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +
>> + ctx->enabled = true;
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_get_modes(struct drm_panel *panel)
>> +{
>> + struct drm_display_mode *mode;
>> +
>> + mode = drm_mode_duplicate(panel->drm, &default_mode);
>> + if (!mode) {
>> + DRM_ERROR("failed to add mode %ux%ux@%u\n",
>> + default_mode.hdisplay, default_mode.vdisplay,
>> + default_mode.vrefresh);
>> + return -ENOMEM;
>> + }
>> +
>> + drm_mode_set_name(mode);
>> +
>> + mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
>> + drm_mode_probed_add(panel->connector, mode);
>> +
>> + panel->connector->display_info.width_mm = mode->width_mm;
>> + panel->connector->display_info.height_mm = mode->height_mm;
>> +
>> + return 1;
>> +}
>> +
>> +static const struct drm_panel_funcs otm8009a_drm_funcs = {
>> + .disable = otm8009a_disable,
>> + .unprepare = otm8009a_unprepare,
>> + .prepare = otm8009a_prepare,
>> + .enable = otm8009a_enable,
>> + .get_modes = otm8009a_get_modes,
>> +};
>> +
>> +/*
>> + * DSI-BASED BACKLIGHT
>> + */
>> +
>> +static int otm8009a_backlight_update_status(struct backlight_device *bd)
>> +{
>> + struct otm8009a *ctx = bl_get_data(bd);
>> + u8 data[2];
>> +
>> + if (!ctx->prepared) {
>> + DRM_WARN("lcd not ready yet for setting its backlight!\n");
>> + return -ENXIO;
>> + }
>> +
>> + if (bd->props.power <= FB_BLANK_NORMAL) {
>> + /* Power on the backlight with the requested brightness */
>> + data[0] = MIPI_DCS_SET_DISPLAY_BRIGHTNESS;
>> + data[1] = bd->props.brightness;
>> + otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
>> + /* set Brightness Control & Backlight on */
>> + data[1] = 0x24;
>> + } else {
>> + /* Power off the backlight: set Brightness Control & Bl off */
>> + data[1] = 0;
>> + }
>> +
>> + /* Update Brightness Control & Backlight */
>> + data[0] = MIPI_DCS_WRITE_CONTROL_DISPLAY;
>> + otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
>> +
>> + return 0;
>> +}
>> +
>> +static const struct backlight_ops otm8009a_backlight_ops = {
>> + .update_status = otm8009a_backlight_update_status,
>> +};
>> +
>> +static int otm8009a_probe(struct mipi_dsi_device *dsi)
>> +{
>> + struct device *dev = &dsi->dev;
>> + struct otm8009a *ctx;
>> + int ret;
>> +
>> + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> + if (!ctx)
>> + return -ENOMEM;
>> +
>> + ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
>> + if (IS_ERR(ctx->reset_gpio)) {
>> + dev_err(dev, "cannot get reset-gpio\n");
>> + return PTR_ERR(ctx->reset_gpio);
>> + }
>> +
>> + mipi_dsi_set_drvdata(dsi, ctx);
>> +
>> + ctx->dev = dev;
>> +
>> + dsi->lanes = 2;
>> + dsi->format = MIPI_DSI_FMT_RGB888;
>> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
>> + MIPI_DSI_MODE_LPM;
>> +
>> + drm_panel_init(&ctx->panel);
>> + ctx->panel.dev = dev;
>> + ctx->panel.funcs = &otm8009a_drm_funcs;
>> +
>> + ctx->bl_dev = backlight_device_register(DRV_NAME "_backlight", dev, ctx,
>> + &otm8009a_backlight_ops, NULL);
>> + if (IS_ERR(ctx->bl_dev)) {
>> + dev_err(dev, "failed to register backlight device\n");
>> + return PTR_ERR(ctx->bl_dev);
>> + }
>> +
>> + ctx->bl_dev->props.max_brightness = OTM8009A_BACKLIGHT_MAX;
>> + ctx->bl_dev->props.brightness = OTM8009A_BACKLIGHT_DEFAULT;
>> + ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
>> + ctx->bl_dev->props.type = BACKLIGHT_RAW;
>> +
>> + drm_panel_add(&ctx->panel);
>> +
>> + ret = mipi_dsi_attach(dsi);
>> + if (ret < 0) {
>> + dev_err(dev, "mipi_dsi_attach failed. Is host ready?\n");
>> + drm_panel_remove(&ctx->panel);
>> + backlight_device_unregister(ctx->bl_dev);
>> + return ret;
>> + }
>> +
>> + DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready\n",
>> + default_mode.hdisplay, default_mode.vdisplay,
>> + default_mode.vrefresh,
>> + mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
>> +
>> + return 0;
>> +}
>> +
>> +static int otm8009a_remove(struct mipi_dsi_device *dsi)
>> +{
>> + struct otm8009a *ctx = mipi_dsi_get_drvdata(dsi);
>> +
>> + mipi_dsi_detach(dsi);
>> + drm_panel_remove(&ctx->panel);
>> +
>> + backlight_device_unregister(ctx->bl_dev);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id orisetech_otm8009a_of_match[] = {
>> + { .compatible = "orisetech,otm8009a" },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(of, orisetech_otm8009a_of_match);
>> +
>> +static struct mipi_dsi_driver orisetech_otm8009a_driver = {
>> + .probe = otm8009a_probe,
>> + .remove = otm8009a_remove,
>> + .driver = {
>> + .name = DRV_NAME "_panel",
>> + .of_match_table = orisetech_otm8009a_of_match,
>> + },
>> +};
>> +module_mipi_dsi_driver(orisetech_otm8009a_driver);
>> +
>> +MODULE_AUTHOR("Philippe Cornu <philippe.cornu at st.com>");
>> +MODULE_AUTHOR("Yannick Fertre <yannick.fertre at st.com>");
>> +MODULE_DESCRIPTION("DRM driver for Orise Tech OTM8009A MIPI DSI panel");
>> +MODULE_LICENSE("GPL v2");
>
>
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